Re: SWI-Prolog is open source

Paulo Moura wrote Wed Dec 4 11:52:45 MET 2013:

> I have been following closely the discussion on SWI-Prolog V7 features and changes. I deeply appreciate Jan commitment to move SWI-Prolog forward and the insightful comments of several people in the list, specially Richard. But I'm also saddened by the tone of some of the comments and accusations flying around. Jan published a document on "SWI-Prolog future directions" at:
> 
> 	
> http://www.swi-prolog.org/Directions.txt
> 
> 
> This document includes the following sentence:
> 
> 	"And, of course, SWI-Prolog is open source, so you are free to fork it under the conditions of the license."
> 
> Is worth repeating: SWI-Prolog is open source. This means that:
> 
> - Jan is sharing the source code of his hard work (it didn't have to)
> - Jan choose an open source code license that allows others to use, modify, and redistribute changes to his work (it didn't have to)
> 
> It also means that:
> 
> - Jan is free to evolve his Prolog implementation in any direction that he finds best for his goals
> - Jan is free to make (what other people perceive as) mistakes
> - Jan is under no obligation to implement any standards
> - Jan is under no obligation to ditch or backtrack on his design decisions for his work
> 
> It's good when open source developers, like Jan, seek out, listen, and consider feedback from their user community in particular and the Prolog community in general (it didn't have to). But users expectations are not open source developer obligations. Anyone expecting otherwise better educate himself or herself on what is and what is not open source. Or be prepared to sign a payed contract for the stuff their work requires.
> 
> An healthy ecosystem welcomes changes, mutations. Some of them strive, become widespread. Some don't survive in the mid. long term. But there's no healthy ecosystem without experimentation, outliers, rebels against what others may perceive as righteous paths.

I agree, but I can also understand that people switching to SWI Prolog 7 may worry if their code still runs as expected. 

It would be interesting to know how many people will stick to SWI Prolog 6 – I will for the time being – and how many will switch to SWI Prolog 7. Further, it would be interesting to learn of the experiences of the "switchers".

Regards.

   --- nef